Vehicle immobilisation device

ABSTRACT

A vehicle immobilisation device ( 60 ) is provided for securing to a vehicle windscreen, comprising screening means ( 46   a;    46   b ) which is changeable from a first, more compact configuration to a second configuration and which, when the device is in an in-use disposition on the vehicle windscreen, serves to impair a driver&#39;s view through the windscreen. Suction grip means ( 40   a;    40   b ) are provided for holding said screening means in the in-use disposition on the windscreen by suction. Release means ( 51 ) are also provided to enable release of the suction of said suction grip means so as to allow removal of the device from the windscreen.

The present invention relates to a vehicle immobilisation device.

Wheel clamp devices are in common use today for dealing with illegallyparked vehicles. Such a wheel clamp device is attached to the wheel ofan illegally parked vehicle by a wheel clamp operative so as to preventthe owner of the vehicle from driving the vehicle away. At the same timeas deploying the wheel clamp device on the illegally parked vehicle, thewheel clamp operative will usually display a notice in the window of thevehicle informing the owner that the vehicle is illegally parked andthat the wheel clamp device will remain on the vehicle until such a timeas a penalty fee is paid. When the owner of the vehicle has contactedthe authorities and paid the penalty fee, the wheel clamp operative isinstructed to return to the vehicle to remove the wheel clamp device,after which the owner of the vehicle is free to remove the vehicle.

One problem with such existing wheel clamp devices is that, in order tobe effective in immobilising the vehicle as well as strong and secureenough to prevent unauthorised removal of the device (by means of forceor otherwise), they tend to be very bulky and heavy. Furthermore, thecomplexity of many such wheel clamp devices makes the successful andsecure deployment very difficult to achieve for an inexperienced wheelclamp operative. The wheel clamp operative can also be put at a greatrisk when deploying a wheel clamp device on a vehicle that is parkedflush to an obstacle on one side (for example a kerb), forcing theoperative to work in the flow of oncoming traffic on the exposed side ofthe vehicle. Wheel clamp devices are also often ineffective againstlarge-wheeled vehicles such as trucks and buses.

It is therefore desirable to provide a vehicle immobilisation devicewhich is free from the above-mentioned problems associated with the useof traditional wheel clamp devices.

According to a first aspect of the present invention there is provided avehicle immobilisation device for securing to a vehicle windscreen,comprising: screening means which, when the device is in an in-usedisposition on the vehicle windscreen, serves to impair a driver's viewthrough the windscreen, wherein the screening means is changeable from afirst configuration to a second configuration, the first configurationbeing more compact than the second configuration; suction grip means forholding said screening means in said in-use disposition on saidwindscreen by suction; releasing means for enabling release of thesuction of said suction grip means so as to allow removal of the devicefrom the windscreen; and security means for preventing unauthorisedoperation of said releasing means.

According to a second aspect of the present invention there is provideda method for securing a vehicle immobilisation device according to thefirst aspect to a vehicle windscreen, comprising the steps of: arrangingsaid screening means on the vehicle windscreen in said in-usedisposition so as to impair a driver's view through the windscreen;activating said suction grip means so as to hold said screening means insaid in-use disposition on said windscreen; and activating said securitymeans so as to prevent unauthorised operation of said releasing means.

According to a third aspect of the present invention there is provided amethod for removing a vehicle immobilisation device secured to a vehiclewindscreen by a method as claimed in any one of claims 29 to 32,comprising the steps of: de-activating said security means so as toenable operation of said releasing means; operating said releasing meansto deactivate said suction grip means; removing the vehicleimmobilisation device from the vehicle windscreen.

Preferably, the screening means is changeable from a first configurationto a second configuration, the first configuration being more compactthan the second configuration. One advantage of this feature is that thedevice may be more easily transported and/or stored when not in use, andyet may still serve to impair the forward visibility of the driver ofthe vehicle to which the device is secured. Furthermore, it is envisagedthat the size of the screening means may be adapted by the operator sothat the device may better fit a different sized windscreen.

According to a fourth aspect of the present invention, there is provideda screening means of a vehicle immobilisation device, the screeningmeans being changeable from a first configuration to a secondconfiguration, the first configuration being more compact than thesecond configuration and having means for allowing engagement with asuction grip means of the device.

Numerous means by which the screening means may be changed from thefirst, more compact, configuration to the second configuration, will bereadily apparent to the person skilled in the art. For example, thescreening means may comprise a plurality of separate screen portionsarranged and connected, for example by means of hinges, so as to befoldable. Alternatively, the screening means may comprise a plurality ofscreen portions, at least two of which are operable to slide relative toone another in a telescopic fashion. As a further alternative, thescreening means may be rolled up from the second configuration to thefirst configuration and unrolled from the first configuration to thesecond configuration. The screening means may also comprise acombination of a flexible material, such as rubber, which is providedwith a plurality of formings which define one or more axes along whichthe screening means may be conveniently folded.

It will be appreciated that the number and location of the suction gripmeans will preferably, but not essentially, be chosen so as to enablethe screening means to be held in the second configuration when disposedon the vehicle windscreen. For example, a suction grip means may beprovided at or near each of the four corners of the screening means.

Alternatively, it may be advantageous or necessary to provide a means bywhich the screening means can be securely held in the secondconfiguration. Appropriate ways of achieving this will be readilyapparent to the person skilled in the art and include, for example, theuse of bolts, lockable hinges or other latching mechanisms to secure aplurality of hingeably connected screen portions in the secondconfiguration. Alternatively, one or more rigid members may be providedwhich at least partially span across two or more separate screenportions so as to secure the screening means in the secondconfiguration. Similarly, in the case where the screening means may beoperable to be rolled up, one or more rigid members may be usefullyemployed in order to help hold the screening means in the secondconfiguration.

The screening means may be adapted to be secured to the windscreenwhilst still in said first configuration or may be adapted to be securedto the windscreen after being changed to the second configuration.

Reference will now be made, by way of example, to the accompanyingdrawings, in which:

FIG. 1 is a front view of a vehicle to which a vehicle immobilisationdevice according to a first embodiment of the present invention has beensecured;

FIG. 2 is a side view of the vehicle of FIG. 1;

FIG. 3 is a side view of the first embodiment of the present inventionshown in an open state;

FIG. 4 is a plan view showing the first embodiment of the presentinvention in an open state;

FIG. 5 is a plan view showing parts of FIG. 4 in more detail;

FIG. 6 is a schematic diagram for use in explaining the size andpositioning of an embodiment of the present invention;

FIG. 7 shows a variation of the first embodiment of the presentinvention having more than one suction grip;

FIG. 8A is a plan view of a vehicle immobilisation device according to asecond embodiment of the present invention;

FIG. 8B is a side view of part of the second embodiment of the presentinvention;

FIG. 9 shows a third embodiment of the present invention;

FIG. 10 shows a fourth embodiment of the present invention;

FIG. 11 shows a fifth embodiment of the present invention; and

FIG. 12 shows a sixth embodiment of the present invention.

FIG. 1 shows a vehicle immobilisation device 1 according to a firstembodiment of the present invention secured to the exterior of thewindscreen 28 of a vehicle 26, and FIG. 2 is a side view of the samevehicle 26 showing the vehicle immobilisation device 1 secured to thevehicle windscreen 28. The vehicle immobilisation device 1 of the firstembodiment is accompanied by an adhesive sticker 30 fixed onto the frontwindscreen 28 warning the driver of the vehicle that no attempt shouldbe made to move the vehicle 26 or remove the vehicle immobilisationdevice 1.

The vehicle immobilisation device 1 of the first embodiment of thepresent invention will now be described in more detail with reference toFIGS. 3 to 5. The vehicle immobilisation device 1 comprises a housingmember 16 incorporating a suction grip 2, as well as first, second andthird strut members 8, 10 and 12 respectively serving to secure saidsuction grip within the housing member 16. The suction grip 2 can besecured in a pivotal manner within the housing member 16, e.g. by use ofa ball and socket arrangement, so as to provide the device with extraflexibility to cope with windscreen curvature.

The suction grip 2 is formed in this embodiment as a flexible rubbersuction cup (such suction grips are commonly used in the glazingindustry for the moving of panes of glass), the open end of whichprojects a small distance through a cut-out 3 in the lower face of thehousing member 16. An annular protective layer 4 of high density foam isformed on the lower face of the housing member 16 around the protrudingsuction grip 2, the thickness of the protective layer 4 beingsubstantially the same as the protrusion distance of the suction grip 2.It should be appreciated that, as an alternative to high density foam,rubber may be used.

Further incorporated within the housing member 16 is a pump handle 14which is connected operatively to a suction device (not shown) which isoperated in use to suck air from within the suction grip 2. As shown inFIG. 5, the pump handle 14 is fixed to the strut members 8, 10 and 12 byfixing members 15. The strut members 8, 10 and 12 are fixed to thehousing member 16 by a fixing member 24 secured to the inside of thehousing member 16. A releasing mechanism (not shown) is further providedwithin the housing member 16 which when operated allows air to bere-introduced into the suction grip 2, thereby releasing the suction.

A covering member 18 of the vehicle immobilisation device 1 is hinged tothe housing member 16 by a hinge 22. The dotted outline of the coveringmember 18 in FIG. 3 shows the vehicle immobilisation device 1 of thepresent embodiment in a fully open state, while the solid-line outlineof the covering member 18 shows the vehicle immobilisation device 1 in apartially open state. A retaining strut 20 is provided to retain thecovering member 18 in the partially open state. A security (or locking)mechanism 6 b is provided on the covering member 18 which engages with acorresponding security mechanism 6 a provided on the housing member 16when the covering member 18 is rotated to a fully closed position. Whenthe covering member is in the closed position, the security mechanism 6a, 6 b prevents unauthorised access to and operation of the componentsheld within the housing member 16.

The operation and deployment of the vehicle immobilisation device 1 willnow be described. The vehicle immobilisation device 1 is firstlypositioned on the exterior of the windscreen 28 as shown in FIG. 1 withthe suction grip 2 and protective layer 4 making contact with thewindscreen 28. The vehicle immobilisation device 1 of the firstembodiment forms a continuous opaque screen member which, when in anin-use disposition on the windscreen 28 of the vehicle 26, serves toimpair the view through the windscreen of a driver of the vehicle, so asto make it impossible to drive the vehicle away in a safe and legalmanner. The ideal positioning and size of the screen member will bedescribed below with reference to FIG. 6.

Once in position on the windscreen 28, the covering member 18 is swungopen and retained in a partially open position by use of the retainingstrut 20. Use of such a retaining strut 20 is beneficial since itprevents the covering member 18 moving to a fully open position where itmight make contact with and potentially damage the surface of thevehicle 26 on which the vehicle immobilisation device 1 is beingsecured. Likewise, the high density foam layer 4 protects the vehicle 26and the windscreen 28 from being scratched as the vehicle immobilisationdevice 1 is being fitted.

When the vehicle immobilisation device 1 is in a suitable position onthe vehicle windscreen 28, the pump handle 14 is operated by theoperative to pump air out of the suction grip 2 thereby to create apartial vacuum within the interior of the suction grip 2. The retainingstrut 20 is then released and the covering member 18 is swung down tothe fully closed position. The security mechanism 6 a, 6 b is activatedto lock the vehicle immobilisation device 1 closed so that unauthorisedaccess and operation of the components within the housing member, inparticular the releasing mechanism, is prevented. A warning sticker 30(or alternatively an LED message display sticker) is then adhered to thevehicle windscreen 28 informing the driver of the action he should taketo have the device removed and warning him that attempting to drive thevehicle with the device in place would be an offence, as would anunauthorised attempt to remove the device in any way. The vehicle 26 isthus rendered substantially immobile. The adhesion created by thesuction grip 2 is of such a strength as to make the forceful removal ofthe vehicle immobilisation device from the vehicle windscreen almostimpossible; such an attempt to remove the device would anyway beillegal.

The vehicle immobilisation device 1 is removed from the vehiclewindscreen 28 by first deactivating the security mechanism 6 a, 6 b,opening the covering member 18 to the partially opened state by use ofthe retaining strut 20, and then operating the releasing mechanism (notshown) to release the partial vacuum from the suction grip 2. Thevehicle immobilisation device 1 can then be removed from the vehiclewindscreen 28 and stowed away for subsequent re-application.

When the vehicle immobilisation device 1 is in an armed state andsecured to the vehicle windscreen 28, it sits flush to the windscreen 28with the high-density foam protective layer 4 in contact with thewindscreen 28 and the suction grip 2 holding the device 1 in tightcontact with the windscreen 28. The size of the gap between the housingmember 16 and the windscreen 28 is preferably of the order ofmillimetres, with the gap being filled by the high density foamprotective layer 4. The small size of the gap makes the prising-off ofthe vehicle immobilisation device 1 or the use of other invasive methodsof removal more difficult. In the present embodiment the high densityfoam protective layer 4 not only serves to prevent scratches and thelike to the vehicle windscreen 28 but it also serves as a suction gripprotection mechanism to prevent insertion of a piercing instrument orthe like which may be used in an attempt to pierce the suction grip 2.Use of a toughened rubber compound for the suction grip is alsobeneficial to make piercing more difficult should this be attempted.

As shown in FIG. 2, the vehicle immobilisation device 1 assumes asubstantially flat profile on the vehicle windscreen 28. The lateraldimensions of the vehicle immobilisation device 1 are determined by thebasic requirement that the vehicle immobilisation device must serve itspurpose of impairing the forward visibility of a driver of the vehicleto which the device is secured to such an extent as to render thevehicle dangerous and illegal to drive. A very wide screening memberwill provide good vision impairment but may result in a vehicleimmobilisation device which is too large or bulky for ease of use, whilea narrower screening member will result in a more lightweight device butwill provide less vision impairment.

FIG. 6 is a schematic diagram showing the relative positions of thevehicle immobilisation device 1, the driver's eye 45 and the driver'sview of the road 40 ahead. For the purpose of this illustration, it isassumed that the vehicle immobilisation device 1 is square-shaped. Thevehicle immobilisation device 1 is preferably positioned on the vehiclewindscreen 28 such that the centre of the vehicle immobilisation device1 is directly in the usual line of sight from the driver's eye 45 to theroad 40 lying ahead of the driver.

The distance d between the driver 45 and the windscreen 28 on which thevehicle immobilisation device 1 is secured will vary from vehicle tovehicle and from driver to driver, but an estimate of the maximumdistance d will serve as a useful guide for the selection of appropriatewidth 2w for the vehicle immobilisation device 1 (the distance islimited by the reach of the driver to the steering wheel). One parameterby which to measure the degree of vision impairment provided by thevehicle immobilisation device 1 is the angle θ shown in FIG. 6. Thegreater the value of θ, the more impairment of the driver's view throughthe windscreen is provided. For effective impairment, the value of θ ispreferably more than 5°, and more preferably greater than 10°, and morepreferably greater than 15°. The width 2w of the vehicle immobilisationdevice 1 is then calculated from the chosen value of θ according to thefollowing formula: w=d Tan θ.

Although the first embodiment has been described as having a singlesuction grip 2 located substantially in the centre of the vehicleimmobilisation device 1, it will be appreciated that a greater number ofsuction grips can be provided and placed at various positions on thevehicle immobilisation device. For example, FIG. 7 shows a vehicleimmobilisation device 1 a that comprises four separate suction grips 2 alocated towards the four corners of the vehicle immobilisation device 1a. Although it is preferable for the high density foam protective layerto cover substantially the entire lower surface of the housing member16, this is by no means essential. For example, in the vehicleimmobilisation device 1 a of FIG. 7 the foam protective layer 4 isconfined to the vicinity around the suction grips 2 a as shown by thedotted lines in FIG. 7. Such a foam layer 4 a is still able to provideprotection against scratches and the like, and it still serves thepurpose of hindering access of an invasive device to the suction grips 2a.

The first embodiment is described above as being provided with its ownmeans for producing the required partial vacuum in the suction grip 2 byway of a pump handle 14 operating a suction device (not shown). It willbe appreciated that it is not necessary to provide a vehicleimmobilisation device embodying the invention with its own means forproducing a partial vacuum, but instead it would be possible to providesuitable means for connecting the suction grip to an external suctiondevice. The operative would simply attach the external suction device tothe vehicle immobilisation device when required in order to create thepartial vacuum in the suction grip.

In the above first embodiment, the covering member 18 serves as theprimary screening member that serves to impair the driver's forwardvisibility, although clearly other parts of the vehicle immobilisationdevice also serve the function of screening, in some degree or another,the view of the road ahead from the driver. For example, the housingmember 16 and the suction grip 2 are both opaque in this embodiment andtherefore act to impair the driver's vision. However, it is the coveringmember 18 in the first embodiment that is principally intended tofunction as the screening member.

In contrast to the first embodiment in which the principal screeningmember is constructed as a single entity, a second embodiment will nowbe described with reference to FIGS. 8A and 8B, in which the screeningmember comprises a plurality of separate sections.

FIG. 8A is a plan view showing a vehicle immobilisation device 1 baccording to a second embodiment of the present invention. The vehicleimmobilisation device 1 b comprises three separate screen portions 11-1,11-2 and 11-3. The vehicle immobilisation device 1 b of the secondembodiment comprises four suction grips 2 b, two of which are located onthe first screen portion 11-1 and the other two of which are located onthe third screen portion 11-3. A security device is provided for each ofthe suction grips 2 b, comprising a security lid 18 b connected by ahinge 22 b to the appropriate screen portion 11-1 or 11-3, the lid 18 bbeing secured by means of a locking mechanism 66. The first screenportion 11-1 is hinged to the second screen portion 11-2 which itself ishinged to the third screen portion 11-3 by use of hinges 50.

FIG. 8B is a side view showing in more detail the construction of one ofthe suction elements of the vehicle immobilisation device 1B. As in thefirst embodiment, a protective layer 4 b is arranged around each suctiongrip 2 b. It will be appreciated that the provision of such a protectionlayer is preferable but not essential. The locking mechanism 66 shown inFIG. 8A is shown in FIG. 8B to comprise a first locking element 66 bprovided on the security lid which engages with a second locking element66 a provided on the screen member concerned (11-3 in FIG. 8B).

In order to save space, in the second embodiment, each suction grip 2 bis not provided with its own suction device and pump handle as in thefirst embodiment. Instead, a pump connection mechanism 70 is providedwhich enables the suction grip 2 b to be connected to an external pumpdevice at the time of securing the device 1 b to the vehicle windscreen.After the suction grip 2 b has been activated so as to provide a grip onthe windscreen, the external pump device is removed from the connectionmechanism, the securing lid 18 b is closed, and the locking mechanism 66is activated to prevent unauthorised removal of the device 1 b.

Removal of the vehicle immobilisation device 1 b of the secondembodiment is achieved by deactivating the locking mechanisms 66 inturn, opening each of the security lids 18 b, and operating thereleasing means so as to deactivate the suction grips. Once removed, thevehicle immobilisation device 1 b can be folded or rolled up for compactstorage.

It will be appreciated that the security lids 18 b of the secondembodiment need not be hinged to one of the screen portions 11-1 to11-3. Instead a security lid may be in the form of a removable cap,preferably secured to the vehicle immobilisation device by a securingwire or the like so as to prevent the loss thereof.

Other arrangements of screen portions and associated folding mechanismswill be readily apparent to the person skilled in the art. For example,FIG. 9 shows a vehicle immobilisation device 1 c comprising two screenportions 33-1 and 33-2, a suction grip 2 c provided on the first screenportion 33-1 and a security lid 18 c connected by a hinge 22 c to thescreen portion 33-1. A locking mechanism 66 c is also provided.

The screen portion 33-2 is provided, at opposing edges 34 and 35, with areceiving section. The screen portion 33-1 is arranged so as to beslideably received within the receiving section in a telescopic fashion,thereby allowing the device to be moveable from a first, more compactconfiguration, to a second configuration large enough to impair adriver's view when disposed on the vehicle windscreen. A pair of rigidmembers 37 a and 37 b are provided on the screen portion 33-2, eachrigid member comprising a foldable strut which may be extended to spanacross both screen portions and secured in an extended configuration bya latch, a locking means or any other suitable means.

FIG. 9A illustrates the device when between the first configuration andthe second configuration, the screen portion 33-1 being partiallyreceived within the receiving section 33-2. The rigid members 37 a and37 b are shown in a folded configuration. FIG. 9B shows the device inthe second configuration, the rigid members shown in an extendedconfiguration. FIG. 9C shows a sectional view through the line A-A.

A further embodiment of the present invention will now be described withreference to FIG. 10.

FIG. 10A shows a plan view of a pair of suction grip means 40 a and 40b. Each suction grip means comprises a flexible rubber suction cup 41and a pump handle 42 a and 42 b operatively connected to the respectivesuction cup. The pump handle comprises a plunger 43 and a releasemechanism 51. The suction grip means 40 a and 40 b are connectedtogether by means of a strut 44, which is formed in two halves 44 a and44 b joined together by means of a double hinge joint 45. Protrusions 52a, 52 b and 52 c are provided on each of the suction cups and the hingejoint 45 (shown more clearly in FIG. 10D).

FIG. 10B shows a pair of rigid screening portions 46 a and 46 b whichare joined together by means of a hinge to form a screening means whichis changeable from a first configuration to a second configuration, thefirst configuration being more compact than the second configuration.When in the second configuration, the screening means exhibits a shapethat substantially conforms to that of a vehicle windscreen. Eachscreening portion is provided with a first covered aperture 47 and asecond aperture 48 and has a strip of rubber around its circumference.In order to accommodate different sized windscreens, the screeningportions of this embodiment each comprise a central section 49 and twoside sections 50 a and 50 b. The side sections are releasably coupled tothe central portion and may be conveniently disconnected in order toadapt the device to fit a smaller sized windscreen.

In order to deploy the vehicle immobilisation device, the suction gripmeans 40 a and 40 b are disposed in the desired position on the vehiclewindscreen. The plunger 43 of each suction grip means is pumped in orderto evacuate air from the suction cup thereby causing it to seal securelyto the windscreen surface. Once sufficient grip has been achieved, thescreening means is placed over the suction grip means so that each pumphandle 42 a and 42 b extends into a respective first covered aperture47, and each protrusion 52 extends into a respective second aperture 48.A so-called disk lock 53 extends through an aperture provided in each ofthe protrusions thereby securing the screening means to the suction gripmeans and preventing access to the release mechanism 51.

The relative positions of the suction grip means and the screeningmeans, when in an in use deployment, is illustrated in FIG. 10C.

A side elevation of the deployed vehicle immobilisation device is shownin FIG. 10D. It can be seen that the configuration of two-part strut 44advantageously allows the curvature of the windscreen upon which thedevice is secured to be accommodated for.

In order to remove the vehicle immobilisation device of this embodiment,the locks 53 must be unlocked so that the screening portions can beremoved thereby allow access to the suction grip means 41 a and 41 b. Arelease 51 is provided which, when pressed, allows air to re-fill thesuction cup so that the suction grip means may be detached.

In this embodiment, the screening portions therefore act as both ascreening means and, coupled with the disk lock and protrusions, asecurity means preventing unauthorised access to the operation of thereleasing means.

A variation of this embodiment comprises a single screen portion, whichis formed of a central section and two side sections. The side sectionsare releasably coupled to the central section and may be convenientlydisconnected in order to adapt the device to fit a smaller sizedwindscreen. The dimensions and shape of the screening means are suchthat, when the device is in an in-use disposition on the vehiclewindscreen, the screening means serves to impair a drivers view throughthe windscreen.

FIGS. 11A to 11C shows a further vehicle immobilisation device embodyingthe present invention. The device 60 comprises suction grip means 61 aand 61 b which function in an identical manner to those described withreference to FIG. 10. In this embodiment, an upper surface of thesuction cups of the suction grip means are sonically welded to aflexible rubber screening means 62. The screening means is provided withrigid formings 63 which are joined together by means of links 64. Theformings 63 serve to impart some rigidity to the otherwise flexiblescreening means and, together with the links 64, serve to preventsomeone from cutting through the rubber in order to access the suctiongrip means.

When not in use, the device may be conveniently folded along the centreline in parallel with formings 63.

In order to deploy the device on a vehicle windscreen, the suction gripmeans 61 a and 61 b, together with the integrally formed screeningmeans, are positioned on the windscreen and the plunger of each ispumped as previously described. Once the desired suction has beenachieved, a pair of security covers 65 a and 65 b each having a coveredaperture for the pump handle of the suction grip means, are lockablysecured thereto by means of a locking means 66 a and 66 b. These alsoserve to press on the formings 63 in order to assist with holding thescreening means in an infuse disposition. The locking means 66 a and 66b are shown more clearly in FIGS. 11B and 11C.

An advantage of this embodiment is that it is relatively light and canbe easily folded for storage. The formings 63 are formed of aluminiumhowever any other rigid material, such as plastic, may be used.

FIG. 12 shows a further embodiment of the present invention. The device70 comprises a suction grip means 71 which is sonically welded to arubber screening means 72 having rigid formings 73 and links 74. Thisembodiment is similar to that shown in FIG. 11 except that it isprovided with only one suction grip means 71, therefore making it lessexpensive to manufacture. A further advantage of this embodiment is itsportability. As can be seen from FIG. 12B, the formings 73 are disposedso as to allow the screening means to be folded up in a concertinafashion. A locking means 76, illustrated in FIGS. 12C and 12D, isfurther provided to inhibit access to the release mechanism of thesuction grip means.

Although the principal use of a vehicle immobilisation device embodyingthe present invention has been suggested as being an alternative to atraditional wheel clamp device for dealing with illegally parkedvehicles, it will be appreciated that such a device embodying thepresent invention will find an application in any situation where theremoval of a vehicle is to be prevented. For example an embodiment ofthe present invention can be used as a vehicle security device toprevent theft of the vehicle to which it is secured. It is thereforeenvisaged that embodiments of the present invention may be utilised bycar vehicle owners/drivers as an anti-theft device. Such an embodimentcould additionally or alternatively be used as a frost protection means.Furthermore, it is envisaged that embodiments of the present inventionmay, on the outer surface of the screening means, be light reflective.In this respect, the outer surface of the screening means could beprovided with a light reflective surface.

1. A vehicle immobilisation device for securing to a vehicle windscreen,comprising: a screen which, when the device is in an in-use dispositionon the vehicle windscreen, serves to impair a driver's view through thewindscreen, wherein the screen is changeable from a first configurationto a second configuration, the first configuration being more compactthan the second configuration; a grip for holding said screen in saidin-use disposition on said windscreen by suction; a release mechanismfor enabling release of the suction of said grip so as to allow removalof the device from the windscreen; and a security mechanism forpreventing unauthorized operation of said release mechanism.
 2. Avehicle immobilisation device as claimed in claim 1, further comprisinga pump handle that is operable by the user of the vehicle immobilisationdevice to produce the suction in the grip.
 3. A vehicle immobilisationdevice as claimed in claim 2, wherein said pump handle is formed andarranged so as to serve also as a grip handle for lifting and carryingthe vehicle immobilisation device.
 4. A vehicle immobilisation device asclaimed in claim 1 ,further comprising a housing for said releasingmechanism, and a cover moveable between an open position allowing accessto said release mechanism and a closed position preventing access tosaid release mechanism, said security mechanism serving to lock saidcover in said closed position.
 5. A vehicle immobilisation device asclaimed in claim 4, wherein said cover comprises a hinged lid.
 6. Avehicle immobilisation device as claimed in claim 4, wherein said coveralso acts as said screen.
 7. A vehicle immobilisation device as claimedin claim 1, wherein a plurality of said grips are provided and wherein acover and security mechanism are provided separately for each of saidgrips.
 8. A vehicle immobilisation device as claimed in claim 1, furthercomprising a protective layer arranged to cushion the vehicle windscreenfrom contact with the device during fitting and when in said in-usedisposition on said vehicle windscreen.
 9. A vehicle immobilisationdevice as claimed in claim 8, wherein said protective layer is formed ofhigh density foam.
 10. A vehicle immobilisation device as claimed inclaim 1, further comprising a grip protector for preventing access tosaid grip from an under-side of the device facing the windscreen when insaid in-use disposition.
 11. A vehicle immobilisation device as claimedin claim 9, wherein said protective layer is arranged around saidsuction grip means so as to serve as a grip protector.
 12. A vehicleimmobilisation device as claimed in claim 1, wherein said device assumesa substantially flat profile when in said in-use disposition.
 13. Avehicle immobilisation device as claimed in claim 1, wherein parts ofthe device visible from the exterior of a vehicle when the device is insaid in-use disposition on the vehicle are decorated in a highly visiblefinish.
 14. A vehicle immobilisation device as claimed in claim 13,wherein said highly visible finish is a reflective finish.
 15. A vehicleimmobilisation device as claimed in claim 1, wherein said screencomprises a plurality of screen portions.
 16. A vehicle immobilisationdevice as claimed in claim 15, wherein said screen portions are arrangedand connected so as to be foldable or operable to be rolled up.
 17. Avehicle immobilisation device as claimed in claim 1, wherein said screencomprises two screen portions which are hingeably connected together.18. A vehicle immobilisation device as claimed in claim 1, wherein saidscreen comprises rubber.
 19. A vehicle immobilisation device as claimedin claim 1, wherein the screen further comprises a plurality of rigidformings.
 20. A vehicle immobilisation device as claimed in claim 18,wherein said screen is sonically welded to the suction grip.
 21. Avehicle immobilisation device as claimed in claim 1, where said gripcomprises one or more suction cups.
 22. A vehicle immobilisation deviceas claimed in claim 1, wherein the width of the device is of the orderof 2d Tan θ, where d is an estimate of the distance from the driver'seye to the vehicle windscreen, and θ is greater than 5°.
 23. A methodfor securing a vehicle immobilisation device as claimed in claim 1, to avehicle windscreen, comprising the steps of: changing said screen fromsaid first configuration to said second configuration; arranging saidscreen on the vehicle windscreen in said in-use disposition so as toimpair a driver's view through the windscreen; activating said grip soas to hold said screen in said in-use disposition on said windscreen bymeans of suction; and activating said security mechanism so as toprevent unauthorized operation of said release mechanism.
 24. A methodas claimed in claim 23, wherein said screen is arranged on said vehiclewindscreen such that the centre of the screen is substantially in thedriver's line of vision.
 25. A method as claimed in claim 23, whereinthe vehicle immobilisation device is placed on the exterior of thevehicle windscreen.
 26. A method as claimed in claim 23 furthercomprising the step of applying an information sticker to thewindscreen.
 27. A method for removing a vehicle immobilisation devicesecured to a vehicle windscreen by a method as claimed in claim 23,comprising the steps of: de-activating said security mechanism so as toenable operation of said release mechanism; operating said releasemechanism to deactivate said suction grip; removing the vehicleimmobilisation device from the vehicle windscreen; and changing saidscreen from said second configuration to said first configuration.
 28. Amethod of preventing a vehicle from being driven away, comprisingattaching a device as claimed in claim 1 to the vehicle windscreen. 29.A vehicle immobilisation device for securing to a vehicle windscreen,comprising: screening means which, when the device is in an in-usedisposition on the vehicle windscreen, serves to impair a driver's viewthrough the windscreen, wherein the screening means is changeable from afirst configuration to a second configuration, the first configurationbeing more compact than the second configuration; suction grip means forholding said screening means in said in-use disposition on saidwindscreen by suction; releasing means for enabling release of thesuction of said suction grip means so as to allow removal of the devicefrom the windscreen; and security means for preventing unauthorizedoperation of said releasing means.
 30. A method for securing a vehicleimmobilisation device as claimed in claim 29 to a vehicle windscreen,comprising the steps of: changing said screening means from said firstconfiguration to said second configuration; arranging said screeningmeans on the vehicle windscreen in said in-use disposition so as toimpair a driver's view through the windscreen; activating said gripmeans so as to hold said screening means in said in-use disposition onsaid windscreen; and activating said security means so as to preventunauthorized operation of said releasing means.
 31. A method forremoving a vehicle immobilisation device secured to a vehicle windscreenby a method as claimed in claim 30, further comprising the steps of:de-activating said security means so as to enable operation of saidreleasing means; operating said releasing means to deactivate saidsuction grip means; removing the vehicle immobilisation device from thevehicle windscreen; and changing said screening means from said secondconfiguration to said first configuration.